Roe Supercharger - Oil Problem

[nfelmlee]

I'm running a Roe supercharger with a 10lbs pulley. Anytime I run the car hard, the back-pressure pops the dipstick out and shoots oil onto the exhaust manifold (and smokes). I thought the crankcase breather would help, but I have the same issue even with it on there. Anyone have a good solution for this? Am I the only person with this problem?

thanks
-nick

 

[GTSPOWERED]

I have had my Roe system for only a few months and never ran into this problem. The only thing that I had to change is the line from the valve cover to the air box had to be rerouted to an oil catch can.

 

[GR8_ASP]

I don not know the Roe system but any boosted engine should have a check valve between the intake and the crankcase in the PCV line to prevent pressure from entering the crankcase. The 2nd PCV line should be upstream of the supercharger, and after the air filters (to provide a slight pressure drop vs atmospheric.

It can and does work on production supercharged/turbocharged engines. Beats the 60's style breather cap (which does not really work as it releases pressure instead of creating a partial vacuum).

 

[Mr Hemi Head]

I have had my Roe system for only a few months and never ran into this problem. The only thing that I had to change is the line from the valve cover to the air box had to be rerouted to an oil catch can.

I like the location of your catch can, who is the manufacturer? Did you add the mounting bracket?

 

[RedEnuf93]

I have a GEN1 and run 8lbs and have the same problem. Oil catch can did help, but not enough.

This issue occurs at high RPM (5500-6200). I ended up putting little electrical tape outside the dipstick tube and it cured it. I dont like the "tylenol" fix though... Symptom cured, but problem not.

I have ALWAYS had this problem, usually it has only spit oil drops on spark plug wires.

Other than that Roe pulls like a locomotive!

Here's my catchcan. It is located low, next to radiator. Both sides venting to same can, with big filter. It has a valve and tube on the bottom of the can, so it can be drained easily.

 

[99 R/T 10]

I have a K&N oil cap/breather which helps the pressure in the engine escape without the problems y'all are seeing. The problem I run into is if I do a lot of high RPM/Speed runs, it will bleed out of the bottom of the cap with a couple of drops of oil, but does relieve the pressure quite a bit.

 

[Camfab]

I second the check valve.

 

[Paolo Castellano]

I'm running a Roe supercharger with a 10lbs pulley. Anytime I run the car hard, the back-pressure pops the dipstick out and shoots oil onto the exhaust manifold (and smokes). I thought the crankcase breather would help, but I have the same issue even with it on there. Anyone have a good solution for this? Am I the only person with this problem?

thanks
-nick

Nick, there are a couple of things going on here.

1. If you have a 1996 GTS, you can get the updated 1997 and up oil dipstick and tube that goes into the block.

2. The main problem here is the stock breather holes in the front of the valve covers are too small to relieve the crankcase pressure resulting from a boosted application at 10 PSI in the higher RPM range.

When the lines to the catch can are too small, the air cannot escape and the oil goes with it and blows out all over wherever it can get out.

If you drill and tap the top of the valve cover for a -12 A/N fitting and run the -12 lines to the catch can, the problem will be eliminated. -10 will probably be ok as well.

I am having the baffles from my car reproduced from what I made for my car and they will be available for those who want them. Adam Brennan got a pair a while back and they worked great for him.

 

[RAYSIR]

I don't see how you can get BOOST into the crankcase without having an intake gasket blown on the underside or piston rings gone. Intake air or boost air never hits the PCV until it goes into the crankcase either by a leajking gasket or rings. Think about it!! Boost doesn't go into Valve covers unless leak or blowBY. First thing I'd be looking for was where is the air leaking from intake and cylinders to crankcase??? Not some check valve.

 

[Camfab]

Actually if the pcv valve is connected to the intake manifold, it does see boost. The pcv acts like a check valve in most cases. As the motor transitions from vacuum to boost, you are no longer pulling a vacuum on the crankcase. Hence pressure builds up in the motor.

 

[FE 065]

I keep asking about placing the catch can - or more importantly, a filter that might be spewing some oil so close to the serpentine belt and alternator w/o getting any interest in the subject..

I ask because my catch can was much taller (and double walled) than the can pictured here, yet it managed to emit oil mist onto the driver's side fenderwell (where it replaced the w/s washer bottle) now and then.

I just don't see having oil mist slowly coating the serp belt or making its' way inside the alternator as something to take a chance on.

Though there never seemed to be a large accumulation of oil in the can, so I don't think the overspray was due to the amount of oil going into the can. There wasn't much coming out the filter, but enough I'm glad I'd placed it where I did...

 

[nfelmlee]

So the best solution is to tap the valve covers as Paolo suggests? (its a gen1 94 rt/10 btw)

thanks
-nick